11976 results for "cancer rna-seq"

in 17.37 milliseconds.

• Preferential infiltration of unique Vγ9Jγ2‐Vδ2 T cells into glioblastoma multiforme

  Glioblastoma multiforme (GBM) is clinically highly aggressive as a result of evolutionary dynamics induced by cross-talk between cancer cells and a heterogeneous group of immune cells in tumor microenvironment. The brain harbors limited numbers of immune cells with few lymphocytes and macrophages; thus, innate‐like lymphocytes, such as γδ T cells, have important roles in antitumor immunity. Here, we characterized GBM‐infiltrating γδ T cells, which may have roles in regulating the GBM tumor microenvironment and cancer cell gene expression. V(D)J repertoires of tumor‐infiltrating and blood‐circulating γδ T cells from four patients were analyzed by next-generation sequencing-based T-cell receptor (TCR) sequencing in addition to mutation and immune profiles in four GBM cases. In all tumor tissues, abundant innate and effector/memory lymphocytes were detected, accompanied by large numbers of tumor‐associated macrophages and closely located tumor‐infiltrating γδ T cells, which appear to have anti-tumor activity. The immune-related gene expression analysis using the TCGA database showed that the signature gene expression extent of γδ T cells were more associated with those of cytotoxic T and Th1 cells and M1 macrophages than those of Th2 cells and M2 macrophages. Although the most abundant γδ T cells were Vγ9Vδ2 T cells in both tumor tissues and blood, the repertoire of intratumoral Vγ9Vδ2 T cells was distinct from that of peripheral blood Vγ9Vδ2 T cells and was dominated by Vγ9Jγ2 sequences, not by canonical Vγ9JγP sequences that are mostly commonly found in blood γδ T cells. Collectively, unique GBM‐specific TCR clonotypes were identified by comparing TCR repertoires of peripheral blood and intra‐tumoral γδ T cells. These findings will be helpful for the elucidation of tumor-specific antigens and development of anticancer immunotherapies using tumor-infiltrating γδ T cells.

  Dataset EGAD00001004862

• Unraveling mutagenic processes influencing the tumor mutational patterns of individuals with Constitutional Mismatch Repair Deficiency

  Constitutional mismatch repair deficiency (CMMRD), caused by bi-allelic germline variants in one of the mismatch repair (MMR) genes, is a childhood cancer predisposition syndrome that often results in the development of multiple tumors early in life. A better understanding of mutational processes driving subsequent CMMRD tumors could advance optimal treatment. Therefore, we performed a genomic characterization of 41 tumors from 17 individuals with CMMRD. Mutational patterns in these tumors were found to be influenced by multiple factors, including the affected MMR genes, tumor types and somatic polymerase proofreading mutations. Temozolomide treatment left prominent mutational signatures in two second primary hematologic malignancies. Furthermore, a novel indel signature was found in 54% of the tumors, characterized by one base pair cytosine insertions in cytosine homopolymers. In conclusion, the analysis of sequential tumors in individuals with CMMRD reveals diverse mutational patterns influenced by the underlying mutated MMR gene, tumor type and treatment history.

  Study EGAS00001007660

• Chemotherapy induces canalization of cell state in childhood B-cell precursor acute lymphoblastic leukemia

  Comparison of intratumor genetic heterogeneity in cancer at diagnosis and relapse suggests that chemotherapy induces bottleneck selection of subclonal genotypes. However, evolutionary events subsequent to chemotherapy could also explain changes in clonal dominance seen at relapse. We therefore investigated the mechanisms of selection in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) during induction chemotherapy where maximal cytoreduction occurs. To distinguish stochastic versus deterministic events, individual leukemias were transplanted into multiple xenografts and chemotherapy administered. Analyses of the immediate post-treatment leukemic residuum at single-cell resolution revealed that chemotherapy has little impact on genetic heterogeneity. Rather, it acts on extensive, previously unappreciated, transcriptional and epigenetic heterogeneity in BCP-ALL, dramatically reducing the spectrum of cell states represented, leaving a genetically polyclonal but phenotypically uniform population, with hallmark signatures relating to developmental stage, cell cycle and metabolism. Hence, canalization of the cell state accounts for a significant component of bottleneck selection during induction chemotherapy.

  Study EGAS00001004407

• Analysis of Donor Pancreata Defines the Transcriptomic Signature and Microenvironment of Early Neoplastic Pancreatic Lesions

  The adult healthy human pancreas has been poorly studied given lack of indication to obtain tissue from the pancreas in the absence of disease and rapid postmortem degradation. We obtained pancreata from brain dead donors thus avoiding any warm ischemia time. We found that neoplastic lesions occur frequently in healthy organs, in donors as young as in their 3rd decade of life. Using the 10X Genomics Platform, we performed single cell RNA sequencing on 7 donor pancreata, 6 of which we separately sequenced tissue from the pancreas head and tail, for a total of 11 sequencing runs. Of note, because one of our runs (containing sequencing from pancreas head and tail) did not pass qc, our final analysis in our study utilized 6 donor pancreata, 5 of which contained pancreas head and tail sequenced separately. This is a robust single-cell dataset of healthy, nonpathologic pancreas tissue and includes acinar, ductal, and non-epithelial cells (myeloid cells, fibroblasts, endothelial cells, lymphocytes).Briefly, the donor pancreas was dissected by a clinically-trained pancreatobiliary surgeon. The organ was dissected into head, body, and tail, with portions of each placed into DMEM media with 1% BSA/10µM Y27632. Tissue was minced into 1mm3 pieces, then digested with 1 mg/mL collagenase P for 20-30 min at 37°C with gentle agitation. Digested tissue was rinsed three times with DMEM/1% BSA/10µM Y27632, then filtered through a 40µm mesh. Resulting cells were submitted to the University of Michigan Advanced Genomics Core for single cell sequencing using the 10x Genomics Platform. FASTQ files of all sequencing runs along with clinical annotation of donors is available through this dbGaP submission.

  Study phs003229

• Peripheral Blood Transcriptome Analysis of ALS Patients

  Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative disorders which overlap in their clinical presentation, pathology, and genetic origin. An over-representation of autoimmune disorders exists in both ALS and FTD, but this remains an unexplained epidemiologic observation. Expansions of a hexanucleotide repeat (GGGGCC) in the C9orf72 gene (GeneID:203228) are the most common cause of familial ALS and FTD (C9-ALS/FTD), leading to both repeat containing RNA and dipeptide accumulation coupled with decreased C9orf72 protein expression in brain and peripheral blood cells. Here we show that loss of C9orf72 in myeloid cells is sufficient to recapitulate the age dependent lymphoid hypertrophy and autoinflammation seen in complete C9orf72-/- mice. Dendritic cells isolated from C9orf72-/- mice showed marked early activation of the type I interferon response, and C9orf72-/- myeloid cells were primarily hyperresponsive to activators of stimulator of interferon gene (STING1 GeneID:340061), a key regulator of the innate immune response to cytosolic DNA. STING degradation through the autolysosomal pathway was diminished in C9orf72-/- mice myeloid cells, and blocking STING suppressed hyperactive type I interferon responses in C9orf72-/- myeloid cells and splenomegaly and inflammation in C9orf72-/- mice. Additionally, mice lacking one or both copies of C9orf72 were more susceptible to experimental autoimmune encephalitis, mirroring the susceptibility to autoimmune diseases seen in C9-ALS/FTD patients. Finally, we found that blood derived macrophages, peripheral blood monocytes, and brain tissue from C9-ALS/FTD patients all showed a hyperactive type I interferon signature compared to sporadic ALS/FTD subjects. Collectively, our results indicate that C9-ALS/FTD patients have an altered immunophenotype due to loss of C9orf72 regulation of STING mediated type I interferon activation.

  Study phs002055

• Resistance to Checkpoint Blockade Therapy Through Inactivation of Antigen Presentation

  Although immune checkpoint blockade (CPB) leads to prolonged responses in 15-40% of patients with metastatic melanoma, treatment refractory disease and progression after initial response remain major causes of mortality. While predictors of response have been reported, the common mechanisms of both primary and acquired resistance are poorly understood. To identify mechanisms of resistance and examine the evolving landscape in response to CPB, we performed whole exome sequencing (WES), immunohistochemistry (IHC), and RNA-sequencing (RNAseq) of longitudinal tumor biopsies from 17 metastatic melanoma patients treated with various CPB therapies. We found no significant changes in both mutational and neoantigen loads over time between responders and nonresponders. However, we identified abnormalities in one gene, beta-2-microglobulin (B2M), an essential component of MHC Class I antigen presentation, that were present in samples during disease progression but not regression. In total, we identified B2M aberrations in 29.4% of patients, including multiple early frameshift mutations, loss of heterozygosity (LOH) overlapping B2M, and absence of tumor-specific B2M protein expression. Additional defects in the antigen presentation and IFNγ pathways were identified but were not restricted to progressing lesions in our cohort. In two independent cohorts of 105 and 38 melanoma patients treated with ipilimumab (anti-CTLA4) and pembrolizumab (anti-PD1) respectively, we found that B2M LOH was enriched 3-fold in nonresponders (~30%) vs. responders (~10%) and associated with poorer overall survival (log-rank p=0.01, p=0.006). Loss of both copies of B2M was found only in nonresponders. We also found evidence for association of LOH overlapping IFNGR1 with poorer overall survival exclusively in the anti-PD1 cohort. Thus, B2M loss is likely a common mechanism of primary and acquired resistance to therapies targeting CTLA4 or PD-1.

  Study phs001427

• Analysis of CD20 loss in patients treated with Mosunetuzumab

  CD20 is an established therapeutic target in B-cell malignancies. The CD20xCD3 bispecific antibody mosunetuzumab has significant efficacy in B-cell non-Hodgkin lymphomas (NHL). Since target antigen loss is a recognized mechanism of resistance, we evaluated the contribution of CD20 expression to clinical response in patients with relapsed and/or refractory NHL in the phase 1/2 GO29781 trial (ClinicalTrials.gov: NCT02500407) investigating mosunetuzumab monotherapy. CD20 was studied using immunohistochemistry (IHC), RNA sequencing, and whole-exome sequencing performed centrally in biopsies collected prior to treatment, or as paired samples at pre-dose and on-treatment, or at-progression. Prior to treatment, most patients exhibited a high proportion of tumor cells expressing CD20; however, the proportion of CD20+ tumor cells in 14/293 (6%) patients was <10%. Analyses of paired biopsies from patients during treatment revealed that CD20 levels were maintained in 29/30 (97%), vs patients with samples at-progression, in which 11/32 (34%) showed CD20 loss. Reduced transcription or acquisition of truncating mutations explained most but not all cases of CD20 loss. In vitro modeling confirmed the effect of CD20 variants identified in clinical samples on reduction of CD20 expression and confirmed missense mutations in the extracellular domain that could block mosunetuzumab binding. This study expands knowledge about the occurrence of target antigen loss after anti-CD20 therapeutics to CD20-targeting bispecific antibodies and elucidates the underlying mechanisms for reduced CD20 expression at disease progression that may be generalizable to other anti-CD20 targeting agents. These results also establish the utility of readily-available IHC staining for CD20 as a tool to inform clinical decisions.

  Study EGAS50000000151

• RNAseq: Acquired non-permissive bone marrow microenvironment impairs hematopoietic stem cell proliferation and maintenance and B-cell development post-HSCT

  Defects in B-cell reconstitution upon hematopoietic stem-cell (HSC) transplantation (HSCT) are a common observation, yet the mechanism remains unexplained. The bone marrow (BM) stroma, including mesenchymal stromal cells (MSCs), guides HSC maintenance and B-lymphopoiesis by secreting crucial cytokines. We report acquired, permanent, selective and complete B-cell deficiency in the context of full donor-chimerism in a patient with X-linked lymphoproliferative disease and aimed to identify the contribution of the BM-microenvironment in disrupted B-cell reconstitution post-HSCT. We studied longitudinal BM samples from the patient and his identical twin, both of whom underwent HSCT with the same donor with opposite outcomes in B-cell reconstitution. In the index patient BM, we observed progressive loss of proliferation of HSCs and a selective block at the pre-BI cell stage. In vitro modeling studies showed limited survival of patient-HSCs and a relative accumulation of pre-B cells. Patient-derived MSCs failed to support survival and proliferation of HSCs and B-cell development of healthy-HSCs which was correlated with reduced CXCL12 levels. Using bulk RNA-sequencing of MSCs and in vitro functional studies, we showed global changes in the patients’ MSCs and a progressive loss of CXCL12 expression. Indeed, survival of patients HSCs improved supplementing in vitro development culture with CXCL12, suggesting a contribution of defective CXCL12 signaling to the phenotype. In summary, our data show that an acquired defect in the BM-stromal microenvironment and exhaustion of HSCs and committed progenitors may cause a permanent non-permissive state for normal B-cell development.

  Study EGAS50000001437

• Stromal-induced epithelial-mesenchymal transition induces drug resistance in acute lymphoblastic leukemia

  Bone marrow (BM) microenvironment-induced drug resistance in acute lymphoblastic leukemia (ALL) is thought to be mediated by intercellular interaction of leukemic cells with BM niches, but the mechanistic basis of resistance is poorly understood. Here, we genomic and functional analyses, we show that ALL-BM mesenchymal stromal cells (MSC) interactions encompass direct cell-cell adhesion via integrin α4β1, uni-directional secretion of soluble factors from MSC to ALL, and bidirectional transfer of cellular vesicles through tunneling nanotubes. We show that this crosstalk drives an epithelial-mesenchymal transition (EMT)-like program in ALL cells adhering to MSC, thereby triggering stem cell-like features including drug resistance and survival advantage. Moreover, single-cell RNA sequencing of cell line and primary ALL samples identified a hybrid cell state derived from B-ALL adhered to MSC, that exhibits both B-ALL and MSC gene signatures that are orchestrated by an EMT-like program. Multiple EMT-activating pathways including WNT/β-catenin, cytokine/STAT3, TGFβ, NOTCH1, and NF-κB-dependent signaling pathways are activated in MSC-adherent ALL cells; however, only the inhibition of either WNT/β-catenin or cytokine/STAT3 pathway could attenuate the survival and drug resistance of ALL cells adherent to MSC. Notably, we identified that this hybrid cell state exhibited elevated WNT/β-catenin-mediated transcriptional activity. Finally, we show that blocking of the interaction of β-catenin and CBP interaction abrogates the survival and drug resistance of ALL cells adhered to MSC, indicating that targeting of an EMT-like program is potential therapeutic regimen in targeting cell extrinsically acquired drug resistance in ALL.

  Study EGAS00001006120

• THAP11 mutations in a patient with a cblX-like phenotype implicates THAP11 in the regulation of cobalamin metabolism and early vertebrate development

  Mutations in HCFC1 are associated with cblX (MIM309541), an X-linked recessive disorder, characterized by defects in cobalamin metabolism and other developmental defects. HCFC1 is a transcriptional co-regulator, which interacts with transcription factors to regulate the expression of a myriad of genes. Notably, HCFC1 regulates cobalamin metabolism via the regulation of MMACHC expression through its interaction with THAP11, a THAP domain-containing transcription factor. In addition, the HCFC1/THAP11 complex potentially regulates genes involved in diverse cellular functions including cell cycle, proliferation, and transcription. Thus, it is likely that mutations in THAP11 may also result in biochemical and other phenotypes similar to those observed in patients with cblX. We report a patient who presented with phenotypic features that overlap cblX, but did not have any mutations in either MMACHC or HCFC1. We sequenced THAP11 by Sanger sequencing and discovered a potentially pathogenic, homozygous variant in THAP11, c.240C>G (p.Phe80Leu). Functional analysis in the developing zebrafish embryo, demonstrate that both THAP11 and HCFC1 regulate the proliferation and differentiation of neural precursors, suggesting important roles in normal brain development. Further, the loss of THAP11 in zebrafish embryos, results in craniofacial abnormalities including the complete loss of Meckel’s cartilage, the ceratohyal, and all of the ceratobranchial cartilages. These data are consistent with our previous work which demonstrated a role for HCFC1 in vertebrate craniofacial development. Furthermore, our high throughput RNA-sequencing analysis reveals several overlapping gene targets of HCFC1 and THAP11 that likely contribute to the phenotypes associated with cblX and related disorders. Thus, both HCFC1 and THAP11 play important roles in the regulation of cobalamin metabolism as well as other pathways involved in early vertebrate development.

  Study EGAS00001002201